VAT on US invoices

I have spoken to Helplines and nearly driven myself mad reading HMRC guidelines about the treatment of VAT for a customer in USA. The three situations are:

1. Training received in USA - client invoiced US supplier for time and expenses – no supply (or as HMRC said no consideration) so outside the scope for VAT. Invoice and associated expenses do not appear on VAT Return. (Strange one this as UK company actually paid for being trained!)

2. Training provided in USA – invoice to US company.

3. Training provided in UK – invoice to US company (for training UK users of their software)

I have come to the conclusion after reading about B2B and Place of Belonging that 2 and 3 are out of scope, but would that mean the associated expenses, especially in example 3 are also out of scope and the input tax not recoverable? I have probably read so much I am now missing the relevant points and the guidance in VAT Notice 741A just seems to go round in circles. Has anyone come across a similar situation?